Fullstack Sr Software Dev Engineer

Yahoo serves as a trusted guide for hundreds of millions of people globally, helping them achieve their goals online through our portfolio of iconic products. We are looking for a Senior Full Stack Software Dev Engineer who is ready to build the next generation of secure, scalable Customer Care systems that serve hundreds of millions of users globally.

Responsibilities:

• Design, build, and operate high-scale Customer Care and Identity systems using React, TypeScript, and Java/Node.js with a strong focus on security and availability
• Lead an AI-first development workflow within the squad, utilizing precise markdown specifications to drive AI-assisted code generation (such as Cursor and Claude Code), while taking ownership of the validation, testing, and safety of all generated assets
• Own complex full-stack features end-to-end, from initial technical requirements and system design to production monitoring and operational excellence
• Proactively identify and implement AI-driven efficiencies in your daily engineering workflows, replacing repetitive manual tasks with structured automation, custom templates, and AI-assisted testing
• Optimize system performance and reliability by diagnosing systemic bottlenecks and proactively implementing AI-assisted performance profiling and diagnostics
• Mentor engineers across the squad, raising engineering standards through peer reviews, detailed design sessions, and scaling modern AI-first development best practices
• Exercise critical technical judgment to audit, validate, and debug AI-generated code outputs, ensuring all implementations meet Yahoo's rigorous security and performance standards
• Collaborate cross-functionally with Product Managers, UX Designers, Security Engineers, and adjacent Yahoo product squads to coordinate complex technical integrations

Requirements:

• Bachelor's degree in Computer Science, a related technical field, or equivalent practical experience
• 5–8 years of professional full-stack software engineering experience
• Strong hands-on engineering experience using Java for robust, secure backend services
• Experience building responsive, high-performance web applications using React.js, Node.js, JavaScript/TypeScript, and modern frameworks (e.g., Next.js)
• Strong fundamentals in system design, RESTful APIs, distributed systems, and web security protocols
• Proven expertise in prompt engineering, context modeling, and structured interaction with AI development environments to build and refactor production-grade systems
• Demonstrated experience integrating AI-assisted developer tools (e.g., Cursor, Claude Code, GitHub Copilot) into day-to-day software development workflows
• Proven capability to critically evaluate, audit, and debug AI-generated outputs, ensuring the detection of errors, hallucinations, or security vulnerabilities
• Deep experience with testing frameworks, modern CI/CD pipelines, and maintaining high codebase standards
• Experience building or maintaining high-scale Identity and Access Management (IAM) systems, auth protocols (OAuth, OIDC, SAML), or web security standards
• Experience with CRM and CMS tool integrations
• Cloud platform experience (GCP, AWS) and infrastructure-as-code
• Familiarity with observability tools (Splunk, Grafana, DataDog) and client/server performance profiling
• Experience with structured development methodologies, such as Spec-Driven Development (SDD), API-first design, or AI-assisted diagnostic tools
• Exposure to web accessibility (WCAG) and internationalization (i18n)